Suspicious Duke Malware DLLs Written to Windows Tasks Directory (via file_event)

PremiumReviewedSigma · High · v1
Product
windows
Category
file_event
Author
HuntRule
Published
2026-07-24
Updated
2026-08-28

ATT&CK techniques

Execution → Defense Evasion
  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Priv Esc

  7. Defense Evasion

  8. Cred Access

  9. Discovery

  10. Lateral Movement

  11. Collection

  12. C2

  13. Exfiltration

  14. Impact

What it detects

This rule detects the Duke malware support DLLs being written into the Windows Tasks directory during the APT29 German Embassy campaign side-loading chain. Dropping Mso.dll and AppVIsvSubsystems64.dll into C:\Windows\Tasks stages the side-loading pair for msoev execution. DLL creation in this task directory is abnormal and indicates payload staging.

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Suspicious Duke Malware DLLs Written to Windows Tasks Directory (via file_event)
Pivot detection · T1574.001 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.